CGI Aircraft Systems & Instruments 2 — Questions and Answers
Question 1: What is density altitude, and why is it important?
- Altitude corrected for wind; affects navigation accuracy
- Pressure altitude corrected for nonstandard temperature; affects aircraft performance (Correct answer)
- Height above ground level; affects obstacle clearance
- Altitude where air density equals sea-level density
Correct answer: Pressure altitude corrected for nonstandard temperature; affects aircraft performance
Density altitude is pressure altitude corrected for nonstandard temperature and represents the altitude at which the aircraft 'thinks' it is flying for performance purposes.
Question 2: What happens to indicated airspeed (IAS) and true airspeed (TAS) as altitude increases at a constant power setting?
- Both IAS and TAS increase
- IAS decreases while TAS increases (Correct answer)
- IAS stays constant; TAS decreases
- IAS increases while TAS stays constant
Correct answer: IAS decreases while TAS increases
As altitude increases, air density decreases, so the aircraft must fly faster (higher TAS) to produce the same aerodynamic pressure (IAS).
Question 3: During a static port blockage in flight, what will the altimeter display?
- Zero altitude
- Continually increasing altitude regardless of actual altitude change
- The altitude at which the blockage occurred, remaining frozen (Correct answer)
- Rapidly decreasing altitude
Correct answer: The altitude at which the blockage occurred, remaining frozen
A blocked static port freezes the altimeter, VSI, and airspeed at the readings they had when the blockage occurred.
Question 4: What is the function of the attitude indicator (artificial horizon)?
- Displays magnetic heading
- Shows pitch and bank attitude relative to the natural horizon (Correct answer)
- Measures rate of turn
- Indicates slip or skid conditions
Correct answer: Shows pitch and bank attitude relative to the natural horizon
The attitude indicator uses a gyroscope to display the aircraft's pitch and bank relative to the actual horizon, independent of outside visual references.
Question 5: Which of the following best describes torque effect in a single-engine propeller aircraft?
- The tendency to roll right due to propeller slipstream
- The tendency to roll left as the engine torque reaction acts opposite to propeller rotation (Correct answer)
- A yaw to the right caused by gyroscopic precession
- An increase in airspeed during left turns
Correct answer: The tendency to roll left as the engine torque reaction acts opposite to propeller rotation
Newton's third law causes the aircraft to roll opposite to propeller rotation direction; for a clockwise-rotating prop, the aircraft tends to roll left.
Question 6: What is the purpose of the fuel-air mixture control in a piston aircraft?
- Controls throttle position at altitude
- Adjusts the ratio of fuel to air to maintain engine efficiency as air density changes with altitude (Correct answer)
- Activates the auxiliary fuel pump
- Manages fuel flow between tanks
Correct answer: Adjusts the ratio of fuel to air to maintain engine efficiency as air density changes with altitude
As altitude increases, air density decreases, so the mixture control allows the pilot to lean the fuel-air ratio to maintain optimal combustion efficiency.
CGI Aircraft Systems & Instruments 2
What is density altitude, and why is it important?